Electronic component

ABSTRACT

An electronic component includes: a first substrate having a through-hole; a second substrate opposite the first substrate; a sealing member surrounding a sealing space formed between the first substrate and the second substrate; a functional element having at least a part thereof disposed in the sealing space, and a through-electrode filling the through-hole, the through-hole penetrating the first substrate. The sealing member includes an elastic core part on the first substrate. A metal film is on a surface of the core part and is bonded to the second substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/951,374 filed Nov. 22, 2010, which is a continuation application ofU.S. application Ser. No. 12/236,575 filed Sep. 24, 2008 (now U.S. Pat.No. 7,863,529 issued on Jan. 4, 2011). This application claims thebenefit of Japanese Patent Application No. 2007-287634 filed Nov. 5,2007. The disclosures of the above applications are incorporated hereinby reference in their entireties.

BACKGROUND

1. Technical Field

The present invention relates to an electronic component such as asurface acoustic wave element.

2. Related Art

Electronic components on which a functional element such as asemiconductor element is mounted in a manner allowing an active facethereof to face a substrate are used in various ways. Such electroniccomponents use the functional element itself as a substrate for forminga sealing space. In the electronic components, the functional element isdisposed in a manner allowing an active face thereof to face asubstrate, so that the active face is positioned inside the sealingspace that is formed between the substrate and the functional element.Here, in such electronic components, measures for maintaining anenvironment inside the sealing space are taken in order to secure normaloperation of the electronic components. For example, JP-A-11-87406,JP-A-11-97584, JP-A-2000-77458, and JP-A-2003-92382 disclose a methodfor sealing an active face in a sealing space by bonding a functionalelement and a substrate with resin or solder.

However, it has been required to improve air-tightness of the sealingspace in related art electronic components.

SUMMARY

An advantage of the present invention is to provide an electroniccomponent in which air-tightness of a sealing space is improved.

The present invention employs structures of the following aspect. Anelectronic component according to an aspect of the invention includes: afirst substrate; a second substrate; a sealing member surrounding asealing space formed between the first substrate and the secondsubstrate; and a functional element at least a part of which is disposedin the sealing space. In the electronic component, the sealing memberincludes a core part formed on the first substrate and having elasticityand a metal film formed on a surface of the core part, and the metalfilm is bonded to the second substrate.

According to the aspect, the core part elastically deforms, so that evenif a surface of the region, contacting the sealing member, of the secondsubstrate has an uneven shape or the second substrate has a warpage, themetal film and the second substrate are favorably bonded to each otherin a sufficient bonding area. Thus, the sealing member can providesufficient air-tightness in the sealing space. That is, when the sealingmember and the second substrate are relatively compressed in the bondingof the first substrate and the second substrate, the core partelastically deforms together with the metal film in a manner following asurface shape of the second substrate. Therefore, a contacting areabetween the second substrate and the metal film increases. Accordingly,the metal film and the second substrate are bonded to each other withsufficient strength.

Further, since the core part elastically deforms, even if the firstsubstrate and the second substrate have different thermal expansioncoefficients from each other, the bonding state between the metal filmand the second substrate can be maintained. Even in a case where apeeling strength is generated between the first substrate and the secondsubstrate in a heat cycle test and the like, the sealing member deformsto follow deformation of the first substrate and the second substratedue to the core part that elastically deforms. Thus, air-tightness ofthe sealing space can be favorably maintained.

In the electronic component of the aspect, it is preferable that abonding metal film metal-bonded with the metal film be formed in aregion, the region contacting with the sealing member, of the secondsubstrate.

According to the aspect, the metal film and the bonding metal film aremetal-bonded so as to bond the first substrate and the second substratein a manner forming the sealing space.

In the electronic component of the aspect, it is preferable that themetal film and the bonding metal film be bonded to each other at normaltemperature.

According to the aspect, the metal film and the bonding metal film arebonded to each other at normal temperature, being able to suppressoccurrence of thermal expansion of the first and second substrates andthe functional element. This eventually improves air-tightnessreliability of the sealing space. Further, the bonding at normaltemperature can prevent the functional element from being damaged byheat.

In the electronic component of the aspect, it is preferable that thesealing member be thermally compressed on the second substrate.

In the aspect, the metal film is thermally compressed to the secondsubstrate so as to be bonded with the second substrate.

The electronic component of the aspect further includes a maintainingmember maintaining a bonding state between the metal film and the secondsubstrate.

In the aspect, the maintaining member maintains the bonding statebetween the metal film and the second substrate, being able to furtherimprove the air-tightness reliability of the sealing space.

In the electronic component of the aspect, it is preferable that themaintaining member surround a periphery of the sealing member.

According to the aspect, the bonding state between the metal film andthe second substrate can be more securely maintained. Further, a lateralface, which is at a sealing space side, of the sealing member is noteasily contaminated, being able to suppress characteristic change of thefunctional element.

In the electronic component of the aspect, the functional element ofwhich a characteristic is changed by stress or heat may be placed on aface of one of the first substrate and the second substrate.

According to the aspect, characteristic change of the functional elementby external stress or heat stress can be kept to the minimum. That is,even if the electronic component receives external stress or is exposedto an environment having a temperature change to receive heat stresscaused by a difference between thermal expansion coefficients of thefirst and second substrates, the core part elastically deforms, beingable to prevent warpage or deformation of the first and secondsubstrates. Therefore, characteristic change of the functional elementcaused by external stress or heat stress can be suppressed.

In the electronic component of the aspect, the functional element may bedirectly formed on a face of one of the first substrate and the secondsubstrate.

According to the aspect, even though the functional element is moredirectly affected by one of the first and second substrates, the corepart elastically deforms even when the electronic component receivesexternal stress or heat stress, preventing warpage or deformation of thefirst and second substrates as the above. Therefore, characteristicchange of the functional element caused by external stress or heatstress can be suppressed.

In the electronic component of the aspect, the functional element may beplaced and bonded on a face of one of the first substrate and the secondsubstrate.

According to the aspect, even if the electronic component receivesexternal stress or heat stress, the core part elastically deforms as theabove, making difficult the functional element bonded to one of thefirst and second substrates to deform due to the bonding part.Therefore, characteristic change of the functional element caused byexternal stress or heat stress can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a sectional view schematically showing an electronic componentaccording to a first embodiment.

FIG. 2 is an enlarged view of FIG. 1.

FIG. 3 is a perspective view showing a semiconductor substrate.

FIG. 4 is a partial enlarged view of FIG. 2.

FIG. 5 is an enlarged sectional view showing a sealing member.

FIG. 6 is an explanatory diagram showing a bonding step of the sealingmember and a sealing substrate.

FIG. 7 is a perspective view showing a cellular phone including anelectronic component.

FIGS. 8A and 8B are sectional views showing another structure of asealing member that is applicable.

FIGS. 9A and 9B are sectional views showing yet another structure of asealing member that is applicable.

FIG. 10 is a sectional view schematically showing an electroniccomponent according to a second embodiment.

FIG. 11 is a partial enlarged view of FIG. 10.

FIG. 12 is a sectional view schematically showing an electroniccomponent according to a third embodiment.

FIG. 13 is a perspective view showing a quartz crystal resonator.

FIG. 14 is a perspective view showing another quartz crystal resonator.

FIG. 15 is a sectional view schematically showing an electroniccomponent according to a fourth embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS First Embodiment

An electronic component according to a first embodiment of the presentinvention will now be described with reference to the accompanyingdrawings. It should be noted that scales of members in the drawingsreferred to hereinafter are adequately changed so that they can berecognized. FIG. 1 is a sectional view schematically showing anelectronic component. FIG. 2 is an enlarged view of FIG. 1. FIG. 3 is aperspective view showing a semiconductor substrate. FIG. 4 is anenlarged sectional view showing a sealing member. FIG. 5 is anexplanatory drawing showing a bonding step of the sealing member and asealing substrate.

Electronic Component

An electronic component 1 according to a first embodiment is a surfaceacoustic wave resonator composed of a surface acoustic wave element(hereinafter, referred to as a SAW element) and a semiconductor element,and is mounted on a circuit substrate P by bumps B, as shown in FIG. 1.Referring to FIG. 2, the electronic component 1 includes a semiconductorsubstrate (a first substrate) 2, a sealing substrate (a secondsubstrate) 3, a surface acoustic wave (SAW) element (a functionalelement) 4, and a sealing member 5.

The semiconductor substrate 2 is a silicon substrate, for example. On afirst face 2A of the semiconductor substrate 2, the SAW element 4 isformed. On a second face 2B of the semiconductor substrate 2, anintegrated circuit (not shown), a lower layer 11, an electrode 12, afirst insulating film 13, a plurality of first wirings 14, a secondinsulating film 15, a plurality of second wirings 16, and bumps B areprovided.

The integrated circuit includes other electronic elements such as atransistor and a memory element.

The lower layer 11 is made of an insulating material such as silicondioxide (SiO₂), for example, and covers the second face 2B of thesemiconductor substrate 2.

The electrode 12 is made of a conductive material such as titanium (Ti),titanium nitride (TiN), aluminum (Al), and copper (Cu), for example, andformed on an under surface of the lower layer 11. The electrode 12 isadequately coupled with the integrated circuit described above.

The first insulating film 13 is made of an insulating material such aspolyimide resin, silicone-modified polyimide resin, epoxy resin,silicon-modified epoxy resin, acrylic resin, phenol resin,benzocyclobutene (BCB), and polybenzooxazole (PBO). The first insulatingfilm 13 is formed on a region, on which the electrode 12 is not formed,of the under surface of the lower layer 11.

Each of the plurality of first wirings 14 is made of a materialcontaining at least one of Cu, chrome (Cr), Ti, nickel (Ni),titanium-tungsten (TiW), gold (Au), silver (Ag), Al, nickel-vanadium(NiV), W, TiN, and lead (Pb), or formed by layering at least two ofthese materials. The first wirings 14 are formed on an under surface ofthe first insulating film 13 and a part of them is coupled to theelectrode 12.

The second insulating film 15 is made of an insulating material similarto that of the first insulating film 13 or an insulating material suchas SiO₂ and silicon nitride (SiN), and covers a part of the firstinsulating film 13 and a part of the first wirings 14. In the firstwirings 14, a region that is not covered by the second insulating film15 is a land portion 17.

The second wirings 16 are formed on an under surface of the secondinsulating film 15 and is coupled to the land portion 17.

The bumps B are made of a conductive material such as lead-free solderand gold, and are coupled to the second wirings 16. The bumps Bfunctions as terminal electrodes of the electronic component 1, and arecoupled to a wiring pattern P1 formed on the circuit substrate P.

As shown in FIGS. 2 and 3, the semiconductor substrate 2 is providedwith a pair of through-holes 21 penetrating the semiconductor substrate2. The through-holes 21 are filled with through-electrode 22. A thirdinsulating film 23 is provided at an inner circumferential face of thethrough-holes 21 of the semiconductor substrate 2, so that thethrough-electrode 22 and the semiconductor substrate 2 are electricallyinsulated.

Referring to FIG. 3, one end of one of the pair of through-holes 22 iscoupled to an interdigital electrode 42 described later and the otherend is coupled through the electrode 12 to the integrated circuit. Oneend of the other of the pair of through-holes 22 is coupled to aninterdigital electrode 43 described later and the other end is coupledthrough the electrode 12 to the integrated circuit. Thus, the SAWelement 4 and the integrated circuit are electrically connected.

Referring to FIG. 2, the third insulating film 23 is formed in order toprevent occurrence of current leak and erosion of the semiconductorsubstrate 2 by oxygen or moisture. The third insulating film 23 may bemade of tetra ethyl ortho silicate (Si(OC₂H₅)₄; hereinafter referred toas TEOS) formed by plasma enhanced chemical vapor deposition (PECVD),that is, PE-TEOS; and TEOS formed by ozone CVD, that is O₃-TEOS; or SiO₂formed by CVD. The third insulating film 23 may be made of otherinsulating material such as a resin material as long as the material hasinsulating properties. Here, FIG. 2 omits the third insulating film 23formed on the first insulating film 13 so as to simplify the drawing.

The sealing substrate 3 is a glass substrate, for example. The sealingsubstrate 3 is disposed to be opposed to the first face 2A of thesemiconductor substrate 2 in a manner spacing out with respect to thesemiconductor substrate 2. Referring to FIGS. 2 and 4, in a region,overlapping with the sealing member 5 in a planar view, of a first face3A of the sealing substrate 3, a bonding metal film 31 is formed. Thefirst face 3A faces the semiconductor substrate 2.

The bonding metal film 31 is a film made of a metal material such as Au.The bonding metal film 31 is formed in the region overlapping with thesealing member 5 in a planar view to have a rectangular frame shape.

The sealing substrate 3 is bonded to the semiconductor substrate 2 withthe sealing member 5 so as to form a sealing space 32 surrounded by thesealing member 5 between the substrates. In the sealing space 32, theSAW element 4 is sealed. It is preferable that the sealing space 32 besubstitution-sealed or vacuum-sealed, that is, the inside of the sealingspace 32 be substituted with dry air or nitrogen, or the sealing space32 have lower pressure than that outside thereof in order to suppresssurface oxidation of the SAW element 4 or binding of water molecules.

As shown in FIGS. 2 and 3, the SAW element 4 is formed on the first face2A of the semiconductor substrate 2 and includes a piezoelectric thinfilm 41 formed on the first face 2A of the semiconductor substrate 2 anda pair of interdigital electrodes 42 and 43 formed on the piezoelectricthin film 41.

The piezoelectric thin film 41 is made of a piezoelectric material suchas zinc oxide (ZnO), aluminum nitride (AlN), lithium niobate (LiNbO₃),lithium tantalate (LiTaO₃), and potassium niobate (KNbO₃).

Each of the interdigital electrodes 42 and 43 is made of a conductivematerial such as Al. Each of the interdigital electrodes 42 and 43 iselectrically connected to one end of one of the through-electrodes 22.

The SAW element 4 is covered by a protection film (not shown) made ofSiO₂, silicon nitride (Si₃N₄), or TiN, for example.

Referring to FIGS. 2 to 5, the sealing member 5 is formed on the firstface 2A of the semiconductor substrate 2 to have a rectangular frameshape surrounding the sealing space 32 in a planar view. The sealingmember 5 includes a resin core (core part) 51 made of a resin materialhaving elasticity and a metal film 52 formed on a surface of the resincore 51.

The resin core 51 is made of a photosensitive insulation resin or athermosetting insulation resin. Specifically, the resin core 51 is madeof polyimide resin, acrylic resin, phenol resin, silicone resin,silicone modified polyimide resin, epoxy resin, or the like.

As shown in FIGS. 3 and 5, the resin core 51 is formed to have anapproximate vault shape in a state before the sealing member 5 is bondedto the sealing substrate 3. The vault shape means a columnar shape ofwhich an inner face (under face) contacting with the first face 2A ofthe semiconductor substrate 2 is flat and outer face beingnon-contacting face is curved. Specifically, the approximate vault shapemay have a cross-section in an approximate half circle, an approximatesemi-ellipsoid, and an approximate trapezoid.

As shown in FIGS. 2 and 4, if the semiconductor substrate 2 and thesealing substrate 3 are pressed so as to relatively come close eachother, the end shape of the resin core 51 elastically deforms to followthe surface shape of the bonding metal film 31.

Therefore, even if the semiconductor substrate 2 and the sealingsubstrate 3 have a warpage or a swell, the resin core 51 follows thewarpage or the swell so as to maintain a favorable sealing state.Further, even if some dirt or cracks are in a sealing region, afavorable sealing state is similarly maintained.

Further, even when a temperature environment of a sealed object ischanged in a case where the semiconductor substrate 2 and the sealingsubstrate 3 are made of different materials so as to have differentthermal expansion coefficients from each other, thermal stress is noteasily generated at the sealing part because the resin core 51elastically deforms. Therefore, the inside of the sealing space is noteasily subjected to thermal stress.

In a case where the whole of the electronic component 1 (SAW resonator)is externally stressed, the stress is not easily transmitted to theinside of the sealing space due to the elastic deformation of the resincore 51. Therefore, even if a device that is sensitive to heat or stressis disposed inside the sealing space, the device is hardly affected bydisturbances, being able to provide a stable electronic component (SAWresonator).

The resin core 51 is formed by photolithography or etching. A quality ofmaterial (degree of hardness) and a shape of the resin core 51 areadequately selected and designed depending on a shape and the like ofthe bonding metal film 31.

The metal film 52 covers the surface of the resin core 51 as shown inFIGS. 3 to 5. The metal film 52 is made of a metal such as Au, TiW, Cu,chrome (Cr), Ni, Ti, W, NiV, Al, palladium (Pd), and lead-free solder,or an alloy of these, and may be a single layer of one of these or amultilayer of these. The metal film 52 deforms to follow the surfaceshape of the bonding metal film 31 due to the deformation of the resincore 51 and is metal-bonded with the bonding metal film 31.

The metal film 52 is formed by patterning a film formed by sputtering,for example. Alternatively, the metal film 52 may be formed by layeringupper-layer films by electroless plating after a lower film is formed bysputtering or electroless plating. Here, it is preferable that the metalfilm 52 be made of Au especially having an excellent flatting property,as described later, because the resin core 51 deforms to follow theshape of the bonding metal film 31. In a case where the metal film 52has a layered structure, it is preferable that the outermost layer ofthe metal film 52 be made of Au that is stable and has an excellentfollowing property to an uneven surface. As is the case with the resincore 51, the metal film 52 is adequately selected and designed dependingon the shape and the like of the bonding metal film 31. Thus theoutermost layer of the superficial layer of the resin core 51 is a metalso as to provide a high gas-barrier property that has not been obtainedin related art resin sealing structures. Thus, the sealing structure ofthe embodiment of the present invention combines the best properties ofmetal and resin, compared to related art sealing structures such as astructure employing highly rigid material such as metal that absorbs nostress and a structure employing resin having a low gas-barrierproperty.

Method for Manufacturing Electronic Component

A method for manufacturing the electronic component 1 will be describedwith reference to FIG. 6. The method is characterized by a bonding stepof the semiconductor substrate 2 and the sealing substrate 3, so thatonly the bonding step will be described. FIG. 6 is a diagram showing thebonding step of the semiconductor substrate and the sealing substrate.

The resin core 51 is formed on the semiconductor substrate 2 in a mannersurrounding a forming region of the sealing space 32, and the resin core51 is covered by the metal film 52. On the other hand, the bonding metalfilm 31 is formed on the surface of the sealing substrate 3 in a mannersurrounding the forming region of the sealing space 32.

Each of the surfaces of the metal film 52 formed on the semiconductorsubstrate 2 and the bonding metal film 31 formed on the sealingsubstrate 3 is activated by removing impurities by plasma irradiation,for example.

Then, as shown in FIG. 6, the sealing member 5 provided on thesemiconductor substrate 2 is brought into contact with the bonding metalfilm 31 formed on the sealing substrate 3 so as to be pressed. At thistime, the resin core 51 elastically deforms, so that the metal film 52deforms in accordance with the deformation of the resin core 51 tofollow the surface shape of the bonding metal film 31. Therefore, themetal film 52 and the bonding metal film 31 contact with each other in asufficient area. Since each of the surfaces of the metal film 52 and thebonding metal film 31 is activated, metals of the surfaces arerelatively diffused, whereby the metal film 52 and the bonding metalfilm 31 are metal-bonded with each other. Accordingly, the semiconductorsubstrate 2 and the sealing substrate 3 are bonded to each other withthe sealing member 5 in a manner sealing the SAW element 4 inside, asshown in FIG. 4. Thus, the semiconductor substrate 2 and the sealingsubstrate 3 are bonded to each other. In the embodiment, a bondinginterface has a sealing structure by the metal bonding, substantiallyimproving a gas-barrier property (air-tightness).

Here, if an environmental atmosphere in the bonding is nitrogen, theinside of the sealing space 32 is substituted with nitrogen, and if theatmosphere is other gas, the inside of the sealing space can besubstituted with a desired gas. Alternatively, if the bonding isconducted in vacuumed atmosphere, the inside of the sealing space 32 isvacuum-sealed. As described above, if the bonding is conducted after thesubstrates undergo the plasma irradiation under vacuumed atmosphere andare arranged in the vacuumed atmosphere, the metals are diffused stablyeven in low temperature in a high degree of activity at the bondingregion, being able to provide high bonding reliability.

Then the electronic component 1 is coupled to the wiring pattern P1through the bumps B formed on the second face 2B of the semiconductorsubstrate 2, and a resin 55 is applied so as to seal a gap formedbetween the electronic component 1 and the circuit substrate P.

Electronic Apparatus

The electronic component 1 described above is applied to a cellularphone 100, for example, as shown in FIG. 7. FIG. 7 is a perspective viewshowing the cellular phone.

This cellular phone 100 includes a display 101, a plurality of operatingbuttons 102, an ear piece 103, a mouth piece 104, and a main body havingthe display 101.

As described above, according to the electronic component 1 of theembodiment, the metal film 52 and the bonding metal film 31 arefavorably metal-bonded in a sufficient bonding area due to the elasticdeformation of the resin core 51. Therefore, sufficient air-tightness inthe sealing space 32 by the sealing member 5 can be provided.

Here, the metal film 52 and the bonding metal film 31 are bonded atnormal temperature, being able to prevent characteristic change of otherelements such as the SAW element 4.

A sealing member 110 having a structure shown in FIGS. 8A and 8B isapplicable in the embodiment. Referring to FIG. 8A, a metal film 111 ofthis sealing member 110 covers a top and an inner face, which faces thesealing space 32, of the resin core 51. If the semiconductor substrate 2and the sealing substrate 3 are bonded with the sealing member 110having such structure, the resin core 51 is drawn into the sealing space32, as shown in FIG. 8B, in a case where the pressure of the sealingspace 32 is lower than that outside the sealing space 32. Accordingly,it becomes easy for the inner face of the resin core 51 to contact withthe bonding metal film 31. Therefore, even if the metal film 111 doesnot cover an outer face of the resin core 51, the bonding area of themetal film 111 and the bonding metal film 31 can be sufficientlysecured.

Similarly, a sealing member 115 having a structure shown in FIGS. 9A and9B is applicable in the embodiment. Here, the pressure of the sealingspace 32 is higher than that outside the sealing space 32. Referring toFIG. 9A, a metal film 116 of this sealing member 115 covers a top and anouter face, which is apart from the sealing space 32, of the resin core51. If the semiconductor substrate 2 and the sealing substrate 3 arebonded to each other with the sealing member 115 having such structure,the resin core 51 is pressed toward the outside of the sealing space 32,as shown in FIG. 9B, because the pressure of the sealing space 32 ishigher than that outside the sealing space 32. Accordingly, it becomeseasy for the outer face of the resin core 51 to contact with the bondingmetal film 31. Therefore, even if the metal film 116 does not cover theinner face of the resin core 51, the bonding area of the metal film 116and the bonding metal film 31 can be sufficiently secured.

Second Embodiment

An electronic component according to a second embodiment of the presentinvention will now be described with reference to the accompanyingdrawings. FIG. 10 is a sectional view showing an electronic component,and FIG. 11 is a partial enlarged view of the FIG. 10. The bondingstructure of the semiconductor substrate and the sealing substrate inthe second embodiment is different from that in the first embodiment, sothat the bonding structure will be mainly described. In the secondembodiment, elements described in the first embodiment will be given thesame reference numerals and the description thereof will be omitted.

Referring to FIG. 10, in an electronic component 120 according to thesecond embodiment, the semiconductor substrate 2 and the sealingsubstrate 3 are bonded to each other with the sealing member 5 and anadhesive layer (maintaining member) 121.

The adhesive layer 121 is an adhesive made of epoxy resin or an acrylicresin, for example. The adhesive layer 121 is formed in a rectangularframe shape in a planar view so as to surround the sealing member 5.

The electronic component 120 of the second embodiment has anadvantageous effect similar to that of the first embodiment. However,the bonding state between the metal film 52 and the bonding metal film31 is maintained by the adhesive layer 121, so that air-tightnessreliability of the sealing space 32 is further improved. In addition,the adhesive layer 121 surrounds the outer periphery of the sealingmember 5, so that characteristic change of the SAW element 4 can besuppressed.

Third Embodiment

An electronic component according to a third embodiment of the presentinvention will now be described with reference to the accompanyingdrawings. FIG. 12 is a sectional view showing an electronic component,and FIG. 13 is a perspective view showing a quartz crystal resonator.The structure of the functional element in the third embodiment isdifferent from that in the first embodiment, so that the structure ofthe functional element will be mainly described. In the thirdembodiment, elements described in the first and second embodiments willbe given the same reference numerals and the description thereof will beomitted.

Referring to FIG. 12, this electronic component 130 of the thirdembodiment is provided with a quartz crystal resonator 131 as afunctional element. Referring to FIG. 13, the quartz crystal resonator131 is a tuning-fork type quartz crystal resonator, and includes acrystal piece 132; a pair of excitation electrodes 133 and 134 excitingthe crystal piece; and bump electrodes 135 and 136.

The crystal piece 132 is a plate like member having an approximateU-shape in a planar view, that is, having a tuning-fork like planar viewin which two arms 132 b and 132 c extend in a same direction in parallelfrom a base part 132 a.

The excitation electrode 133 is formed, on one face of the crystal piece132, along the arm 132 b from the base part 132 a. The excitationelectrode 134 is formed, on the one face of the crystal piece 132, alongthe arm 132 c from the base part 132 a.

The bump electrodes 135 and 136 are electrically connected with theexcitation electrodes 133 and 134 respectively. Referring to FIG. 12,the bump electrode 135 is coupled to a connecting electrode 137 formedon the first face 2A of the semiconductor substrate 2 and electricallyconnected with one of the pair of through-electrodes 22. The bumpelectrode 136 is coupled to a connecting electrode 138 formed on thefirst face 2A of the semiconductor substrate 2 and electricallyconnected with the other of the pair of through-electrodes 22.

The electronic component 130 having such structure is manufactured bybonding the semiconductor substrate 2 and the sealing substrate 3 afterthe quartz crystal resonator 131 is mounted on the semiconductorsubstrate 2.

As above, the electronic component 130 of the third embodiment has anadvantageous effect similar to that of the above embodiments. As is thecase with the second embodiment, the semiconductor substrate 2 and thesealing substrate 3 may be bonded to each other with the adhesive layer121.

The quartz crystal resonator 131 is not limited to the tuning-fork typequartz crystal resonator, but may be a quartz crystal resonator shown inFIG. 14. This quartz crystal resonator 140 is used in a gyro sensor, forexample, and includes a crystal piece 141, driving electrodes 142 and143, detecting electrodes 144 and 145, and bump electrodes 146 through149. These electrodes are formed on one face of the crystal piece 141.

The crystal piece 141 includes a fixing part 151, a pair of driving arms152 and 153, and a pair of detecting arms 154 and 155.

The driving arm 152 includes a base part 152 a formed to protrude fromthe fixing part 151 and an end part 152 b connected with the base part152 a. An extending direction of the base part 152 a and an extendingdirection of the end part 152 b are approximately orthogonal to eachother. The base part 152 a is connected to an approximate center of theend part 152 b.

The driving arm 153 includes a base part 153 a formed to protrude fromthe fixing part 151 and an end part 153 b connected with the base part153 a. An extending direction of the base part 153 a and an extendingdirection of the end part 153 b are approximately orthogonal to eachother. Therefore, the extending direction of the end part 153 b and thatof the end part 152 b are approximately parallel to each other. Aprotruding direction of the base part 153 a from the base part 151 isopposite to that of the base part 152 a. The base part 153 a isconnected to an approximate center of the end part 153 b.

The detecting arms 154 and 155 are formed to protrude from the fixingpart 151. A protruding direction of the detecting arm 154 from thefixing part 151 is opposite to that of the detecting arm 155. Anextending direction of each of the detecting arms 154 and 155 isapproximately orthogonal to the extending direction of each of the basepart 152 a and 153 a and is approximately parallel to the extendingdirection of each of the end parts 152 b and 153 b.

The driving electrode 142 is formed on one face of each of the base part152 a and the end part 152 b. The driving electrode 143 is formed on oneface of each of the base part 153 a and the end part 153 b. Thedetecting electrode 144 is formed on one face of the detecting arm 154,and the detecting electrode 145 is formed on one face of the detectingarm 155.

The bump electrodes 146, 147, 148, and 149 are electrically connectedwith the driving electrode 142, the driving electrode 143, the detectingelectrode 144, and the detecting electrode 145 respectively.

Fourth Embodiment

An electronic component according to a fourth embodiment of the presentinvention will now be described with reference to the accompanyingdrawings. FIG. 15 is a sectional view showing an electronic component.The structure of the functional element in the fourth embodiment isdifferent from that in the first embodiment, so that the structure ofthe functional element will be mainly described. In this fourthembodiment, elements described in the first through third embodimentswill be given the same reference numerals and the description thereofwill be omitted.

Referring to FIG. 15, in this electronic component 160 of the fourthembodiment, the SAW element 4 is formed on the first face 3A of thesealing substrate 3. End parts of a pair of through-electrodes 161 areformed in a protruding manner from the first face 2A of thesemiconductor substrate 2 so as to be electrically connected with theSAW element 4.

The sealing member 5 is formed on the first face 3A of the sealingsubstrate 3, and the bonding metal film 31 is formed on the first face2A of the semiconductor substrate 2.

The electronic component 160 of the fourth embodiment has a similaradvantageous effect as that of the above embodiments. As is the casewith the second embodiment, the semiconductor substrate 2 and thesealing substrate 3 may be bonded to each other with the adhesive layer121. Here, the SAW element 4 may be formed on the first face 2A of thesemiconductor substrate 2.

It should be understood that the technical scope of the presentinvention is not limited to the above-mentioned embodiments but appliesto various kinds of modifications without departing from the spirit andscope of the present invention.

For example, the metal film and the bonding metal film are metal-bonded,but they may be bonded to each other with a solder or a brazingmaterial, or by thermocompression. Further, the metal film and thebonding metal film are bonded to each other at normal temperature, butthey may be bonded to each other at high temperature.

The metal film and the sealing substrate are bonded to each other bybonding the bonding metal film formed on the surface of the sealingsubstrate and the metal film, but they may be bonded without the bondingmetal film.

In the first to third embodiments, the sealing member is formed on oneface of the semiconductor substrate, but it may be formed on one face ofthe sealing substrate. In this case, the bonding metal film is formed onone face of the semiconductor substrate.

In the second embodiment, the adhesive layer is formed to have arectangular frame shape in a planar view, but the shape is not limitedto the rectangle as long as the bonding state between the metal film andthe bonding metal film by the sealing member can be maintained. Further,the adhesive layer may be provided inside the sealing space. The bondingstate between the metal film and the bonding metal film is maintained bythe adhesive layer, but it is not limited to the adhesive layer as longas the bonding state can be maintained.

The functional element is not limited to the SAW element, but it may beother functional elements such as a quartz crystal resonator, microelectro mechanical systems (MEMS), and a liquid crystal layer. Here, asdescribed above, the atmosphere in the sealing space may be adequatelyselected in accordance with the functional element.

Similarly, the first substrate is not limited to the semiconductorsubstrate, but may be a substrate made of other materials. The secondsubstrate is not limited to the glass substrate, but may be a substratemade of other materials.

In this case, the first and second substrates are allowed to beelectrically connected with each other by the metal film formed on thesurface of the resin core.

The electronic component is individually manufactured in the aboveembodiments, but a plurality of electronic components may bemanufactured such that after pieces of sealing substrates are bonded ona semiconductor substrate, the bonded body is divided by dicing or thelike. Alternatively, the plurality of electronic components may bemanufactured such that after a sealing substrate is bonded on thesemiconductor substrate, the bonded body is divided by dicing or thelike.

1. An electronic component, comprising: a first substrate having athrough-hole; a second substrate opposite the first substrate; a sealingmember defining a sealing space, the sealing space being surrounded bythe sealing member, the first substrate, and the second substrate; asurface acoustic wave element having at least a part thereof disposed inthe sealing space, and a through-electrode filling the through-hole, thethrough-hole penetrating the first substrate, the through-electrodebeing electrically connected to the surface acoustic wave element,wherein the sealing member includes a resin on the first substrate; anda metal film on a surface of the resin, the metal film being bonded tothe second substrate.
 2. The electronic component according to claim 1,wherein an insulating film is provided along a circumferential face ofthe through-hole.
 3. The electronic component according to claim 1,wherein a bonding film metal-bonded with the metal film is in a regionof the second substrate contacting the sealing member.
 4. The electroniccomponent according to claim 1, wherein an integrated circuit is on anouter face of the first substrate.
 5. The electronic component accordingto claim 4, wherein an insulating film is on outer surface of the firstsubstrate and on the integrated circuit.
 6. An electronic component,comprising: a first substrate having a through-hole; a second substrateopposite the first substrate; a sealing member defining a sealing space,the sealing space being surrounded by the sealing member, the firstsubstrate, and the second substrate; a micro electro mechanical system(MEMS) having at least a part thereof disposed in the sealing space, anda through-electrode filling the through-hole, the through-holepenetrating the first substrate, the through-electrode beingelectrically connected to the MEMS, wherein the sealing member includesa resin on the first substrate; and a metal film on a surface of theresin, the metal film being bonded to the second substrate.
 7. Theelectronic component according to claim 6, wherein an insulating film isprovided along a circumferential face of the through-hole.
 8. Theelectronic component according to claim 6, wherein a bonding filmmetal-bonded with the metal film is in a region of the second substratecontacting the sealing member.
 9. The electronic component according toclaim 6, further comprising an integrated circuit disposed on an outerface of the first substrate.
 10. The electronic component according toclaim 9, wherein an insulating film is disposed on an outer surface ofthe first substrate and on the integrated circuit.